The invention concerns a press for extruding lubricating grease, with a press head with a high-pressure reciprocating pump, a high-pressure outlet opening with check valve, a low-pressure intake opening for feeding to the reciprocating pump the mass to be extruded, a device for actuating the pump piston of the reciprocating pump, and a connection on the press head for connecting a pipe to the press head, the pipe containing a lubricating grease filled, cylindrically shaped cartridge with a displaceable trailing piston.
Such a press, in the form of a hand lever press, is known from DE-A-22 14 652. There, the rigid cartridge displays, in the region of its end facing the press head, a circular bead that is clamped between the pipe screwed into the press head and the press head. The bottom of the cartridge, displaying the outlet opening for the viscous mass, is formed in a convex manner, so that its ring edge abuts the press head. Between the bead of the cartridge and the press head is designed a seal, which is likewise intended to prevent the viscous mass from reaching the ring gap formed between the cartridge and the pipe. The end of the pipe turned away from the press head is formed open, so that the position of the trailing piston lodged displaceably in the pipe, and thus the fill level of the cartridge, can be perceived from outside through the opening. The diameter of the opening in the pipe is dimensioned smaller than the outer diameter of the cartridge. To replace a cartridge, it is thus necessary to unscrew the pipe form the press head, insert a new cartridge with bead from the side of the pipe turned away from the press head, and again screw the pipe onto the press head.
The designs of the lever press and of the cartridge to be found in connection with this application have various disadvantages. Thus, it is quite time-consuming to replace the cartridge, because the press head and the pipe must be separated. Furthermore, provision must be made for sealing means between cartridge and press head or pipe. The cartridge is costly to make, since it is not designed as a component with constant inner and outer diameters, but rather displays a bead. The contents of the cartridge, i.e., the type of lubricating grease, is not recognizable from the outside, since indications as to the lubricating grease located in a particular cartridge are not, as a rule, present in the bottom region of the cylinder section of the cartridge.
Known from U.S. Pat. No. 5, 044, 471 is a hand lever press for extruding lubricating grease. There, instead of a cylindrical cylinder, a bellows cartridge is used. This has, among others, the disadvantage that it does not permit a complete and clean emptying. Clamped between the press head and a pipe screwed into this is an attachment element, which displays a connection for the screwing in of the bellows cartridge. The pipe that surrounds the bellows cartridge is closed in the region of its end turned away from the press head and inside the pipe is arranged a compression spring, which is effective between this end and a piston that impinges upon the bellows cartridge. With increasing emptying, the bellows cartridge is compressed. The fill level of the bellows cartridge inserted into the pipe cannot be perceived from outside. To replace the bellows cartridge, the pipe must be unscrewed from the press head.
Known from GB-A 2 273 745 is likewise a hand lever press for extruding lubricating grease in which a bellows cartridge finds application. This bellows cartridge is screwed directly into the press head in the region of the outlet connection piece of the cartridge and is surrounded by a pipe that is likewise screwed into the press head. The pipe is formed open in the region of its end turned away from the press head. The bellows cartridge is located completely inside the space enclosed by the pipe, so that it is protected against damage from outside during use of the press. In order to enable the fill level of the bellows cartridge to be ascertained, the pipe is provided on its side with a slot that extends in the longitudinal direction of the pipe over a part of its length. According to the fill level of the bellows cartridge and thus to the greater spacing of the circumferential bellows edges when the cartridge is full, or, on the other hand, to the lesser spacing of these bellows edges in the partially or completely empty state, the approximate fill level of the bellows cartridge can be perceived through the slot. Since the bellows cartridge collapses with increasing emptying, for its replacement it is necessary to unscrew the pipe from the press head.
Under the type designation MATO DF 500, a pneumatic one-hand press of the firm MATO Machinen-und Metallwarenfabrik Curt Matthaei GmbH and Co. K G, Mxc3xchlheim, has become known. This displays a main body that is formed in essence by the pressure unit and the press head. Here, the cartridge, after its sealing cap has been removed, is screwed, together with the grease-pressing cylinder, into the press head. Furthermore, pneumatic presses for lubricating grease are known from DE-A-35 27 925.
A dispenser for issuing pasty masses, for example toothpaste, is known from DE-A 40 13 705. In this dispenser, a cylindrical cartridge with a base is used, which cartridge completes a housing that displays a conveying device, arranged in a head piece, for proportioned issuing of the mass from a mouth piece, under the step-by-step advance of a trailing piston arranged in the cartridge. The cartridge is introduced through the lower opening of the housing into a pipe-shaped section of the housing and the cartridge, along with its socket displaying an outer thread, is screwed into a central housing floor, whereby an annular collar forming the base of the cartridge contacts the housing on the face side. This is necessary so that a cylindrical wall of the cartridge is at the correct distance from a pump piston of the dispenser and the latter thus functions correctly. The dispenser standing open in the region of the cartridge is grasped by one hand on the outside in the region of the housing and an actuating handle integrated in the head piece is pressed by one of the fingers of this hand. With this dispenser the cartridge is guided radially by the pipe-shaped section of the housing and the socket is held axially in the central housing floor. The cartridge is fixed through the contacting of its annular collar on the face side at the housing in the region of the lower opening of the housing.
From DE-A-39 24 926 is known a device for applying fluid, for example a cosmetic fluid, ink, dye, or a liquid pharmaceutical. The fluid is located in a cartridge that is inserted into a shaft and projects out of this in the rear. When the cartridge is moved in the longitudinal direction relative to the shaft, the cartridge moves together with a valve unit that works with it; the valve unit issues the fluid, for example onto a brush.
The task of the invention is to further develop a press of the type given in the introduction, in such a manner that cartridges used in it can be exchanged quickly and easily. With this device, the fill level of the cartridge should be perceivable, as well as the type and/or manufacturer of the lubricating grease located inside the cartridge. The sealing between cartridge and press should be ensured. The cartridge should be protected from damage from outside and, on account of the underlying conventional pressing-device type of construction, high stresses during use should be withstood.
The task is accomplished in a press of the type given in the introduction by the fact that provision is made for a cartridge-connecting element that is held between the press head and the pipe, the connecting element displaying a connection for the cartridge, and by the fact that the pipe is formed open in the region of its end turned away from the press head, the cartridge joined to the connecting element projecting from the open end of the pipe, guided by the pipe radially and is held fixed axially through the connecting element.
Thus, in the press according to the invention, provision is made for a cartridge connecting element to which the cartridge is joined, it being essential that the cartridge is inserted into the pipe from the end of the pipe that is turned away from the press head. The sealing of the cartridge results directly at the cartridge-connecting element, which thus forms a stop for the cartridge. The connecting element serves thus not only the holding of the cartridge but also its fixing because of the stop function. Since the cartridge exhibits a greater length than the pipe, the cartridge end protruding from the pipe can be conveniently grasped in order to join the cartridge to the cartridge-connecting element or to separate it from this. In this, it is important that the cylindrical, stiffly designed cartridge protrudes sufficiently far from the pipe. This ensures that the cartridge can be well grasped and firmly screwed in, with the result that an airtight connection between cartridge and connecting piece, necessary for the functioning of the press according to the invention, is produced. Thus, the drawing of the lubricating grease from the cartridge during operation of the press is ensured. Since for replacement of the cartridge the pipe need not be removed from the press head, the cartridge can be replaced very quickly and easily and the operation of the press is substantially simplified. Beyond this, the cartridge is protected by the pipe. The cartridge end protruding from the pipe is marked with indications concerning the type of lubricating grease and/or the manufacturer. Through the fact that the end of the pipe oriented away from the press head is open, the position of the trailing piston of the cartridge can be determined at any time, and thus its fill level.
The cartridge-connecting element can be designed as a separate component or can be integrated into the press head. The latter is of advantage in particular with a press head produced in a molding or casting process. In a preferred implementation form, provision is made for a cartridge-connecting element formed as a separate component that is held between the press head and the pipe.
Preferably, the press is designed as a hand-lever press, one-hand press, or pneumatic press.
If the press is designed as a hand lever press and has only one hand lever, namely that for actuating the pump piston, then the pipe takes on the function of a grip, i.e., during operation the hand lever press is grasped at the grip and the hand lever. The number of components of the hand lever press can be considerably reduced with respect to the conventional hand lever press with the pipe, piston rod, compression spring, collar, and clamp lever. The production costs of the hand lever press according to the invention is therefore correspondingly lower.
The concept of the press according to the invention makes possible a substantially improved tightness compared to a press with a collar. The cartridge is closely joined to the cartridge-connecting element, which for its part is positioned between the pipe and the press head so as to be sealed. The trailing piston is optimally matched to the cartridge.
Preferably, the cartridge-connecting element is designed as a rotationally symmetrical body, with a bead that is wedged between press head and the pipe screwed into the latter, in particular with one or more sealing elements interposed. The cartridge-connecting element is thus positioned between the press head and the pipe during the assembly of the press. Between the cartridge-connection element and the actual bottom of the press head remains a space for receiving the viscous mass, which space is connected to the low-pressure intake opening of the press head. Preferably, this space is so formed that an optimal streaming of the viscous mass out of the cartridge and into the press head is ensured. The sealing between the bead of the cartridge-connection element and the press head is undertaken appropriately by means of a sealing ring, or, in the case of a plastic part, through the part itself.
According to a first preferred implementation form of the invention, the cartridge-connection element is designed so that it has a threaded connection for the cartridge in the region of the outlet opening. Thus, provision is made for a screw connection between the cartridge and the cartridge-connection element. According to an advantageous further development, the cartridge-connection element is disc-shaped and possesses a perforating central threaded bore for receiving a projection of the cartridge displaying an outer thread, the threaded projection being provided with the outlet opening for the viscous mass. Alternatively, the cartridge-connection element can have a connecting piece with an outer thread and an inner opening, the outlet opening of the cartridge having an inner thread. The two above-specified configurations thus require different designs of the cartridge, one the one hand with a projection with an outer thread, and on the other hand an opening with an inner thread made in the base of the cartridge.
According to a second preferred implementation form of the invention, the cartridge-connection element has a plug connector for the cartridge. In this case, in an advantageous further development the cartridge-connection element is designed in a ring-shaped manner, in which the wall strength of the ring can be calculated so as to be relatively low, since in this implementation form, no thread for connecting the cartridge to the cartridge-connection element is required. According to a useful design, the cartridge-connection element is provided with a recess in the region of its outer diameter, centered in the end oriented towards the press head, as well as in the end of the cartridge-connection element oriented away from the press head, for the purpose of inserting the cartridge between the connecting element and the pipe. It is considered especially advantageous if the cartridge-connection element is provided with a groove in the region of its recess for a locking connection to a bead of the cartridge and/or with a groove for receiving a sealing ring, in particular an elastic O-ring.
In principle, also realizable is a one-piece cartridge-connection element, in which through selection of a suitable material both a sealing effect and a fixing can be achieved.
The press so characterized can be loaded with a full cartridge in an especially simple manner, since after the removal of a sealing cap turned towards the press, the cartridge is merely slid into the press pipe and, by means of a thrust, is pressed over the connecting element. Just as easily the empty cartridge can be removed again by a simple pulling away. A further advantage of this solution is the fact that the connecting element can be produced with an inner diameter that approaches the inner diameter of the cartridge, whereby an optimal viscous-mass influx space for the inflow into the inlet opening of the press is provided.
The cartridge-connecting element consists preferably of plastic or metal. The cartridge consists preferably of plastic and is designed as a relatively stiff component. The press head and the pipe consist preferably of metal.
Since the cartridge is screwed or inserted, as the case may be, into the pipe from behind, the outer diameter of the cartridge must be adapted only to the inner diameter of the pipe. In this connection it is suggested that the cartridge be cylinder-shaped and that the outer diameter of the cartridge be slightly smaller than the inner diameter of the pipe, so that the cartridge is seated in the pipe largely without play. Consequently, during the insertion of a new cartridge, the latter is brought into the connection position at the cartridge-connection element in a defined manner. When the cartridge has been inserted into the cartridge-connecting element, the cartridge should protrude from the pipe approximately 20 to 50 mm. On this protruding cartridge end can be marked, for example, the type of grease as well as the supplier.
A specially designed cylindrical cartridge for receiving a viscous mass, in particular lubricating grease, can be used not only with the press designed according to the invention, employing a cartridge-connecting element provided with a thread, but also with conventional presses that have the piston rod and the collar that is prestressed by means of a pring.
Such a universally applicable cylindrical cartridge has a pipe section with inner and outer diameters that remain constant over its length, the trailing piston being seated in the pipe section so as to be displaceable and the cartridge displaying a flat base, which is provided with a central opening for letting the viscous mass out of the cartridge; also, the base possesses an inner thread in the region of the opening. The cartridge formed in this manner can, on the one hand, be screwed onto the cartridge-connecting element displaying the threaded projection, and on the other hand can be used with conventional presses, by virtue of the flat design of the cartridge base. After the retraction of the piston rod and its locking by means of the clamp lever, the cartridge is inserted into the unscrewed pipe from the press-head side and the pipe is again screwed to the press head. In order that the piston rod can be pushed in, the trailing piston is provided with, for example, a central predetermined breaking point. When the piston rod is pushed in, the nose of the piston rod breaks through the predetermined breaking point of the trailing piston and the nose of the piston rod, when the latter is pushed completely into the pipe, passes through the central opening of the cartridge. Through the ring gap between the piston rod, or rather its nose, and the central opening in the cartridge base, the viscous mass can be discharged from the cartridge into the press head upon compression. Instead of the design of the trailing piston with a central predetermined breaking point, it is also possible to fashion the trailing piston in such a manner that it is removed before the insertion of the cartridge into the unscrewed pipe. In this case, the collar presses not upon the trailing piston, but rather directly upon the viscous mass located in the cartridge. In order that a sufficient volume remains between the cartridge and the press head for the viscous mass to continue flowing, in particular in the region of the low-pressure intake opening, the cartridge should have in the region of its base a protruding ring bead, by means of which the cartridge supports itself against the lid of the press head or a sealing element that is adjacent to this.
An empty cartridge is either replaced with a new, full cartridge or it is refilled. The latter is possible without unscrewing the pipe from the press head by, for example, the fact that the press head is provided with a filling valve.
Further features of the invention are presented in the description of the figures and in the figures themselves;